Methods and compositions for improving the nutritional content of mushrooms and fungi

ABSTRACT

An improved filamentous fungi is disclosed that has an enhanced nutritional profile by utilizing pulsed ultraviolet irradiation. According to the invention, the vitamin D component of mushrooms and other filamentous fungi may be drastically increased with no deleterious affects on appearance with the use of pulsed UV radiation. Mushrooms so treated had up to 1800% DV in one serving of fresh mushrooms.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application of U.S. Ser. No. 13/563,065 filedJul. 31, 2012, which is a divisional application of U.S. Ser. No.12/386,810 filed Apr. 23, 2009 (now abandoned), which application claimspriority under 35 U.S.C. §119 of a provisional application Ser. No.61/047,268 filed Apr. 23, 2008, each of which are hereby incorporated byreference in their entirety.

GRANT REFERENCE

This invention was made with government support under Hatch Act ProjectNo. PEN04092, awarded by the USDA and No. 58-0790-6-051, awarded by theUSDA/ARS. The Government has certain rights in the invention.

FIELD OF THE INVENTION

This invention relates to a nutritional product for use in animal feed,foods and beverages and more particularly to a mushroom or fungi havingan increased vitamin content.

BACKGROUND OF THE INVENTION

Mushrooms are valuable health food—low in calories, high in vegetableproteins, chitin, iron, zinc, fiber, essential amino acids, vitamins &minerals. Mushrooms also have a long history of use in traditionalChinese medicine. Their legendary effects on promoting good health andvitality and increasing a body's adaptive abilities have been supportedby Western medicine as well. They are an excellent source of selenium,riboflavin, pantothenic acid, copper, niacin, potassium and phosphorous.Selenium is needed for the proper function of the antioxidant system,which works to reduce the levels of damaging free radicals in the body.Selenium is a necessary cofactor of one of the body's most importantinternally produced antioxidants, glutathione peroxidase, and also workswith Vitamin E in numerous vital antioxidant systems throughout thebody.

Mushrooms are also the only vegetable or fruit which contains Vitamin D,naturally. All other natural food sources of Vitamin D are of animal,poultry or seafood origin. Also, some foods, such as milk, orange juiceand cereals may be fortified with Vitamin D, up to 100 IU.

Vitamin D is a fat-soluble vitamin that is naturally present in very fewfoods, added to others, and available as a dietary supplement. It isalso produced endogenously when ultraviolet rays from sunlight strikethe skin and trigger Vitamin D synthesis. So one must either ingestVitamin D or sit in the sun and soak up UV rays, so that it may besynthesized endogenously. The risks of sun exposure have gained muchattention lately, and the association of sun exposure with Pre-cancerous(actinic keratosis) and cancerous (basal cell carcinoma, squamous cellcarcinoma and melanoma) skin lesions—caused by loss of the skin's immunefunction, fine and coarse wrinkling of the skin, freckles, discolorationof the skin, and Elastosis—the destruction of the elastic tissue causinglines and wrinkles is well documented. Thus as people become moresensitive to the dangers of UV exposure, other dietary sources ofVitamin D become increasingly important for maintaining health.

Vitamin D is essential for promoting calcium absorption in the gut andmaintaining adequate serum calcium and phosphate concentrations toenable normal mineralization of bone and prevent hypocalcemic tetany. Itis also needed for bone growth and bone remodeling by osteoblasts andosteoclasts. Without sufficient Vitamin D, bones can become thin,brittle, or misshapen. Vitamin D sufficiency prevents rickets inchildren and osteomalacia in adults. Together with calcium, Vitamin Dalso helps protect older adults from osteoporosis.

Vitamin D has other roles in human health, including modulation ofneuromuscular and immune function and reduction of inflammation. Manygenes encoding proteins that regulate cell proliferation,differentiation, and apoptosis are modulated in part by Vitamin D. Manylaboratory-cultured human cells have Vitamin D receptors and someconvert 25(OH)D to 1,25(OH)₂D. It remains to be determined whether cellswith Vitamin D receptors in the intact human carry out this conversion.

It is an object of the present invention to provide a food product foruse in foods and beverages which is high in nutritional values,particularly Vitamin D.

It is another object of the invention to provide methods for enhancingthe Vitamin D content of mushrooms.

It is yet another object of the invention to provide such nutritionallyenhanced mushrooms and filamentous fungi without any deleterious affectson the mushrooms appearance.

These and other objects of the present invention will become apparentfrom the description of the invention which follows.

SUMMARY OF THE INVENTION

This invention creates an improved food product with an enhancednutritional profile by utilizing ultraviolet irradiation. The product isobtained by a method comprising the steps of obtaining a mushroom orother fungi the content of Vitamin D or its analogs or derivatives, ofwhich is desired to be increased. The mushroom or fungi is subjected topulsed UV irradiation. Applicants have discovered the dosage and timingof radiation (pulsing) to provide the highest benefit of increasedVitamin D content, without any negative effects on mushroom appearance,shelf life, or nutrients. These benefits were shown to be stable, evenafter more than one week in storage. The pulsed UV minimizes thedamaging effects of ultra-violet radiation both from a mushroom qualityas well as commercial preparation and workplace safety standpoint.Utilizing the irradiation in discrete pulses was shown to enhance theVitamin D content on the order of eight to ten times the content ofVitamin D over non-irradiated mushroom or fungi. The effect was alsodemonstrated to not adversely affect other nutritionally desirablecomponents of mushrooms and was shown to be effective at increasingVitamin D when applied to mushroom tissues, components, or even to spentmushroom substrate. In yet another embodiment, the Vitamin D enrichedmushroom substrate could be used in animal feed or as a nutritionalsource of Vitamin D. Mushrooms are usually produced by first preparing asubstrate, such as corn, rice, millet or rye, prepared by soaking thegrain in water and sterilizing the substrate before inoculation withmushroom spores or mushroom mycelia. Mycelia are the filamentous hyphaeof a mushroom that collect water and nutrients to enable mushrooms togrow. The inoculated substrate is then held to promote colonization ofthe mycelia, at which point the mycelia-laced grains become “spawn”.This is usually done in individual spawn bags. The substrate providesthe nutrients necessary for mycelium growth. The mycelium-impregnatedsubstrate then develops under controlled temperature and moistureconditions, until the hyphae of the mycelium have colonized thesubstrate. The mycelium enriched product usually is harvested afterabout four to eight weeks from the beginning of the process, with thecontents of the spawn bag possibly processed into dry powdered product.According to the invention, this spent substrate may also be enriched inVitamin D upon application of pulsed UV irradiation. As used herein theterm “mushroom” or “filamentous fungi” shall be interpreted to includeall tissues, cells, organs of the same, including but not limited tomycelium, spores, gills, fruiting body, stipe, pileus, lamellae,basidiospores, basidia, and the like.

DETAILED DESCRIPTION OF THE FIGURES

The patent or application file contains at least one drawing executed incolor. Copies of this patent or patent application publication withcolor drawing(s) will be provided by the Office upon request and paymentof the necessary fee.

FIG. 1 is a photograph of UV treated mushrooms by the methods of Feeneyet al.

FIG. 2 is a photograph of pulsed UV treated mushrooms according to theinvention.

FIG. 3 is a graph depicting the Vitamin D₂ content of fresh slicedmushrooms after exposure to pulsed UV-light at 0, 10 and 20 seconds(C-type lamp).

FIG. 4 is a graph depicting the Percent DV of Vitamin D₂ in one servingof fresh sliced mushrooms after exposure to pulsed UV-light at 0, 10 and20 seconds (C-type lamp).

FIG. 5 is a graph depicting the Vitamin D₂ content of fresh slicedmushrooms after exposure to pulsed UV light at 0, 4, 10 and 20 seconds(C-type lamp).

FIG. 6 is a graph depicting the Percent DV of Vitamin D₂ in one servingof fresh sliced mushrooms after exposure to pulsed UV-light (C-typelamp).

FIG. 7 is a graph showing the Percent DV Vitamin D₂ in one serving (84g) of white button mushrooms (Agaricus bisporus) after pulsed UV lightexposure (B-type lamp). Error bars represent standard deviation of thethree replications.

FIG. 8 is a graph depicting the percent DV Vitamin D₂ in one serving (84g) of brown button mushrooms (Agaricus bisporus) after pulsed UV lightexposure (B-type lamp). Error bars represent standard deviation of thethree replications.

FIG. 9 is a graph depicting the percent DV Vitamin D₂ in one serving (84g) of shiitake mushrooms (Lentinula edodes) after pulsed UV lightexposure (B-type lamp). Error bars represent standard deviation of thetwo replications.

FIG. 10 is a graph showing the percent DV Vitamin D₂ in one serving (84g) of oyster mushrooms (Pleurotus ostreatus) after pulsed UV lightexposure (B-type lamp). Error bars represent standard deviation of thetwo replications.

FIG. 11 is a graph showing the vitamin D₂ content of pulsed UV treated(B-type lamp) selenium enriched and normal air-dried Agaricus bisporusmushroom powder.

Samples were treated at a distance of 3.2 cm.

FIG. 12 is a graph showing the Vitamin D₂ and ergothioneine (blacksquares) contents of pulsed UV treated (B-type lamp) king oystermushroom powder. Samples were treated at a distance of 3.2 cm.

FIG. 13 is a graph depicting the Vitamin D₂ content of pulsed UV treated(B-type lamp) king oyster mycelium grown on oat substrate. Samples weretreated at a distance of 3.2 cm in both whole oat and ground powderform.

FIG. 14 is a graph showing the Vitamin D₂ content of pulsed UV treated(B-type lamp) spent king oyster substrate. Samples were treated wet anddry at a distance of 3.2 cm.

FIG. 15 is a graph depicting the Vitamin D₂ content of pulsed UV treated(B-type lamp) spent maitake substrate. Samples were treated at adistance of 3.2 cm before and after air-drying.

FIG. 16 is a graph showing the Vitamin D₂ and ergothioneine (blacksquares) contents of pulsed UV treated (C-type lamp) Agaricus bisporus.Samples were treated at a distance of 8 cm.

DETAILED DESCRIPTION OF THE INVENTION

Previous research (Feeney, 2006) determined that exposing mushrooms toconstant ultraviolet light can produce Vitamin D₂ by converting thenaturally-occurring ergosterol to Vitamin D₂. However, there wereconcerns about compliance with nutrition labeling regulations throughoutretail distribution, deleterious affects on appearance, and tissuebrowning, See FIG. 1. Another significant disadvantage was the increasedlength of exposure time required by conventional sources of UV light,which were impractical in a packinghouse environment. Thus constant UVradiation at sufficient time and strength caused deleterious affects onthe appearance of mushrooms and at best, achieved an increase of 100% ofthe % DV/per serving of Vitamin D but with a host of regulatory, andcommercial processing concerns.

Chikthimmah and Beelman (2006) recently tested pulsed UV-lighttreatments at very high levels for long period of time (30 seconds ormore) to reduce bacterial populations in fresh mushrooms. In this paper,they speculated that Vitamin D₂ content in mushrooms could be rapidlyincreased using pulsed UV-light. The conclusion was, however that suchexposure caused discoloration and deleterious affects on the appearanceof mushrooms, particularly white mushrooms. Such browning of mushroomswould make them commercially undesirable. Bacterial populations areresponsible for the browning and degradation of mushrooms, which has adramatic and negative affect on their appeal to customers.

According to the invention, applicant herein demonstrates that pulsed UVlight at lower ranges and for very brief periods was shown to havedramatic increases in the Vitamin D levels present in such mushrooms,with increases by as much as 800 times the % DV (percent daily value) ofVitamin D content, per serving with no deleterious affects on themorphology or appearance of the mushroom. See FIG. 2. This dramaticincrease in Vitamin D content in light of earlier studies which haddemonstrated less Vitamin D conversion after much longer periods of UVexposure is quite surprising.

Pulsed UV-light treatments to increase Vitamin D₂ content in mushroomswere conducted with a laboratory scale, pulsed light sterilizationsystem (SteriPulse®-XL 3000, Xenon Corporation, Woburn, Mass.) that ispresent in the Department of Agricultural Biological Engineering at PennState. While applicants postulate that it is the UVB component of theXenon pulsed light system that is responsible for the affects of theinvention, it should be noted that the system uses pulsed light whichincludes the entire spectrum of light and may also include othercomponents that contribute to the affects demonstrated herein and whichare intended to be within the scope of the invention.

According to the invention, pulses of UV radiation of approximately 1-10J/cm² per pulse, preferably 3-8 J/cm² and most preferably 5-6 J/cm² isused. Voltages may also vary based upon safety concerns but shouldgenerally be in the range or 1 to 10 or even up to 100 or 10,000 voltsas safety mandates. The pulses should generally be in a range of 1-50pulses per second more preferably 1-30 pulses per second and mostpreferably 1-10 pulses per second for a range of treatment post harvestof 0 to 60 seconds.

Any type of mushroom, mushroom part, component, fungi or even usedsubstrate for cultivating mushrooms, with ergosterol present may beused. This includes all filamentous fungi where ergosterol has beenshown to be present and includes the use of tissues such as the mycelia,spores or vegetative cells. This includes, but is not limited to, forexample, Coprinus, Agrocybe, Hypholoma, Hypizygus, Pholiota, Pleurotus,Stropharia, Gardonerma, Grifola, Trametes, Hercicium, Tramella,Psilocybe , Agaricus, Phytophtora , Achlya, Flammulina, Melanoleuca,Agrocybe, Grifola, Moschella, Mastigomycotina, Auricularia, Gymnopilus,Mycena, Boletus, Gyromitra, Pholiota, Calvatia, Kuegneromyces,Phylacteria, Cantharellus, Lactarius, Pleurotus, Clitocybe, Lentinula(Lentinus), Stropharia, Coprinus, Lepiota, Tuber, Tremella, Drosophia,Leucocoprinus, Tricholoma, Dryphila, Marasmius, and Volvariella.

Non-limiting examples of other fungal genera, including fermentablefungi, include: Alternaria, Endothia, Neurospora, Aspergillus, Fusarium,Penicillium, Blakeslea, Monascus, Rhizopus, Cephalosporium, Mucor, andTrichoderma.

In yet another embodiment, the spent mushroom substrate upon whichmushrooms are cultivated, was enriched in Vitamin D using pulsed UVlight according to the invention. Such spent substrate could then beused as nutritional feed supplements and the like for animals.

The inventors used 5.61 J/cm² per pulse on the strobe surface for aninput voltage of 3800V and with 3 pulses per second. Sliced mushrooms(Agaricus bisporus, white strain) were placed in the pulsed UV-lightsterilization chamber and treated with pulsed light for up to a20-second treatment at a distance of 17 cm from the UV lamp or 11.2 cmfrom the window. Control samples did not undergo any pulsed UVtreatment. Treated mushrooms were freeze-dried and then sent to aselected commercial laboratory for Vitamin D₂ analysis. In this study, apulsed UV system was also evaluated for effects on the appearance offresh mushroom slices during a shelf life study.

Results of the experiments demonstrated that pulsed UV-light was veryeffective in rapidly converting ergosterol to Vitamin D₂. Controlmushrooms contained 2 ppm d.w. Vitamin D₂, while 10 and 20 seconds ofexposure to pulsed UV-light resulted in 17 and 26 ppm Vitamin D₂,respectively (FIG. 3). This increase was equivalent to over 1800% DVVitamin D in one serving of fresh mushrooms after a 20 second exposureto pulsed UV (FIG. 4). The mushrooms treated for 20 seconds also showedno noticeable difference in appearance initially as well as after 10days of storage at 3° C. compared to the untreated control.

These results compared favorably to the previous pilot study (Feeney,2006) where mushrooms were exposed to 5 minutes of conventional UV-lightexposure. In that study, the mushrooms contained 14 ppm Vitamin D₂, butthey were also significantly discolored. Hence, the pulsed UV methodshows considerable promise as a rapid means to enhance Vitamin D₂ levelsin fresh mushrooms, theoretically reducing required exposure times fromminutes to seconds. Pulsed UV-light exposure did not result in anynegative effects on mushroom quality.

Another experiment revealed that pulsed UV-light could rapidly convertergosterol present in dried oyster mushroom powder to Vitamin D₂ (Table1). These findings indicate that this technology could be used to enrichother mushroom products with Vitamin D₂.

TABLE 1 Vitamin D₂ generation in dried oyster mushroom powder exposed topulsed UV-light (C-type lamp). Time of Exposure(s) Vitamin D₂ (PPM) 08.5 8 15.18 16 24.24

The present invention relates to methods for obtaining a nutritionallyenhanced food product using pulsed UV radiation to increase Vitamin Dand/or its derivatives in filamentous fungi. The solid substrate can beany part of the mushroom or mold, including the mycelia, spores etc, solong as ergosterol is present in at least part of the tissue or cells.

In the present invention, the filamentous fungi product is subjected topulsed UV irradiation after harvest, being irradiated with UV light fora time sufficient to enhance the Vitamin D content thereof. By utilizingUV irradiation, the food product has a substantially increased level ofVitamin D. Preferably, the food product is irradiated with UV radiation,specifically Ultraviolet-B (UV-B), a section of the UV spectrum, withwavelengths between about 280 and 320 nm, or Ultraviolet-C (UV-C), withwavelengths between about 200 and 280 nm. In a more preferred embodimentthe UV radiation is pulsed. It is believed that the additional Vitamin Dis obtained through the conversion of ergosterol due to the UVirradiation. The time may be the same or increased when the irradiationoccurs during the growing process, or post harvest though the UVirradiation can occur during both periods.

Example 1

Fresh mushrooms were obtained from Modern Mushroom Farm (Avondale, Pa.)and the Penn State MTDF. All mushrooms were protected from extraneouslight exposure throughout the experiments.

A Steripulse®-XL 3000 (Xenon Corporation, Wilmington, Mass.) was usedfor Pulsed UV light exposure. A B-type lamp was used. The systemgenerated 505 Joules per pulse. At 3.2 cm from the window or 9 cm fromthe lamp, the broadband energy was 0.873 J/cm² per pulse. The systemgenerates 3 pulses per second. All previous experiments were conductedusing a Xenon C-type lamp.

Brown and white button mushrooms were sliced to expose gill tissue. Theywere randomly placed in 150 g lots into polystyrene containers. Oysterand Shiitake mushrooms were divided into 150 g lots and were arranged inthe system so that there was a single layer of mushrooms. All sampleswere placed in the Pulsed UV system at a distance of 3.2 cm from thequartz window.

Brown and white button mushrooms were exposed for 0, 1, 2, 3, and 4pulses. All treatments were repeated three times. Oyster and Shiitakemushrooms were exposed for 0, 1, 2, and 3 pulses. All treatments wererepeated twice.

Mushroom powders from air-dried Agaricus bisporus with and withoutselenium enrichment grown at the Penn State MTDF using the methods ofWerner and Beelman (2002), were treated in 5g lots in uncovered Petriplates at a distance of 3.2 cm from the quartz window. King Oystermushrooms (obtained from Golden Gourmet Mushrooms, San Marcos, Calif.)were air-dried and treated at the same distance. The powders weretreated at 0, 4, 8, and 16 pulses.

Spent mushroom substrates (Maitake and King Oyster) obtained from GoldenGourmet Mushrooms were treated either before or after air drying. Drysamples were treated in 5 g lots and wet samples were treated in 20 glots. The Maitake substrate was treated at 0, 4, and 8 pulses. KingOyster substrates were treated at 0, 8 and 16 pulses.

Commercially dried King Oyster mycelial biomass grown on sterile organicoats at Golden Gourmet Mushrooms (Mushroom Matrix) were treated at 0, 4,8, and 16 pulses before and after being ground into powder form.

The King Oyster mushroom powder was also evaluated for ergothioneinecontent. Ergothioneine content was determined by the method of Dubost etal (2006). Ergothioneine levels are reported as mg/g dry weight.

Mushroom samples were freeze-dried directly following treatment andground into powder. All other samples were air-dried and ground intopowders. The powders were sent to Medallion Labs (Minneapolis, Minn.)for Vitamin D₂ analysis.

Vitamin D₂ values of fresh mushrooms are presented based on the % DV(Adequate Intake of 400 IU) in a serving (84 g) of fresh mushrooms.Vitamin D₂ values for powders and substrates are presented as IU/100 gdry weight.

Results and Discussion

After exposure to increasing amounts of pulsed UV light there was anincrease in Vitamin D₂ content of every mushroom product tested. Witheach additional pulse the mushrooms were exposed to increasing amountsof irradiation and thus more energy was available for Vitamin D₂synthesis from ergosterol.

Fresh sliced white button mushrooms showed an increase from an initialVitamin D₂ level of 0% DV/serving to 325% DV/serving after just onepulse (FIG. 7). After 4 pulses the level of Vitamin D₂ increased to 824%DV/serving.

Fresh sliced brown button mushrooms (FIG. 8) Vitamin D₂ went from aninitial level of 4% DV/serving at 0 pulses to 362% DV/serving after onepulse. The level increased to 899% DV/serving after 4 pulses.

After Pulsed UV treatment fresh Shiitake mushrooms (FIG. 9) showed anincrease in Vitamin D₂ content from an initial level of 3% DV/serving at0 pulses to 490% DV/serving after one pulse. The Vitamin D₂ contentafter 3 pulses was 1200% DV/serving.

Fresh Oyster mushrooms contained an initial level of Vitamin D₂ of 15%DV/serving at 0 pulses to a level of 1618% DV/serving after 3 pulses(FIG. 10).

The Oyster and Shiitake showed higher amounts of Vitamin D₂ contentafter Pulsed UV light exposure than the brown and white buttonmushrooms. This is most likely due to the thickness of the layer ofmushrooms in the system. The brown and white button mushrooms wereplaced in polystyrene containers to simulate a package of slicedmushrooms being treated. The Oyster and Shiitake mushrooms were treatedas whole mushrooms since their geometry did not permit for evendistribution when packed together. The single layer of the Oyster andShiitake mushrooms was similar to how these mushrooms would be treatedif the Pulsed UV system were placed over a line where the mushrooms werebeing transported on a conveyor belt in a single layer. An additionalstudy would be needed to directly compare the Vitamin D₂ content of theAgaricus mushrooms to the Oyster and Shiitake mushrooms.

This study demonstrates that after a very short exposure time of about 1sec (system generates 3 pulses per second) the Vitamin D₂ content ofthese mushroom varieties can be increased from very little to upwards of800% DV/serving. Previous studies using continuous UV light has beenshown to take at least 5 minutes of exposure to obtain similar values(Feeney, 2006).

This study also showed that increasing the Vitamin D₂ contents ofseveral mushroom products such as powders and substrates is possible.This material could be used as food ingredients or for animal feed tocreate value added products.

FIG. 11 shows that the Vitamin D₂ content of selenium enriched (200 ppm)and control (10 ppm) mushroom powder (Agaricus bisporus) were increasedin a similar manner from around 100 IU at 0 pulses to over 100,000 IUper 100 g with a treatment of 16 pulses.

The Vitamin D₂ content of air-dried King Oyster powder was increasedfrom 367 IU at 0 pulses to 91800 IU per 100 g after 16 pulses. Theergothioneine content of the dried products remained constant around 1.3mg/g for all treatments (FIG. 12) indicating that pulsed UV treatmenthad no effect on ergothioneine levels.

Mushroom mycelial biomass grown on sterile organic oats showed similarincreases in Vitamin D₂ with increasing exposure although levels werenot as high as with pure fruiting body material. Vitamin D₂ dried KingOyster mycelial biomass increased significantly when ground from 0 to7100 IU, however when exposed before grinding the level only rose to 288IU (FIG. 13).

King Oyster spent substrates pressed of excess water and treated withpulsed UV light before and after air drying (FIG. 14) showed slightlyhigher Vitamin D₂ content when treated wet (9040 IU compared to 6820 IUat 16 pulses). The opposite effect was seen with Maitake spent substrate(FIG. 15). The undried substrate showed less conversion after 8 pulses(1810 IU compared to 3400 IU).

Pulsed UV technology has been shown to be a more practical method of UVirradiation of mushrooms for the mushroom industry than previous methodsdue to the shorter amount of time needed for exposure to achieve highamounts of Vitamin D₂. The UV-B bulb used in this study was found to behighly effective in converting ergosterol to Vitamin D₂ and would appearto more practical than UV-C bulbs for commercial use since there wouldbe no generation of ozone that could compromise worker safety.

The ergothioneine content of mushrooms in both fresh and powder form didnot appear to change much with pulsed UV treatment. These findings showthat it is possible to produce mushrooms that contain high levels ofselenium, Vitamin D₂ and ergothioneine.

Example 2

An experiment was conducted to determine if pulsed UV light treatmentemployed to enhance the Vitamin D₂ levels could have any negativeeffects on other nutritionally valuable components like the uniqueantioxidant L-ergothioneine. Sliced white button mushrooms were exposedto 0, 20, 30, 40 and 50 seconds of pulsed UV light as described above.The results (FIG. 16) demonstrate that Vitamin D₂ levels increasedsignificantly with increasing time of exposure but L-ergothioneinelevels were relatively unchanged. These data indicate that mushrooms canbe enriched with Vitamin D₂ using pulsed UV light and high ergothioneinelevels are retained.

While preferred embodiments of the present invention have been shown anddescribed, it will be understood by those skilled in the art thatvarious modifications can be made without varying from the scope of theinvention.

What is claimed is:
 1. A filamentous fungi product including, tissues,substrate, spent substrate or components thereof with increased vitaminD content produced by the following method: irradiating said fungi withpulsed UV irradiation from a UV-B source wherein said pulse isapproximately 1-10 J/cm2 per pulse for a period of time of about 0.1 toabout 60 seconds wherein approximately 1-50 pulses per second areprovided, so that Vitamin D is increased without discoloration ordeleterious effects on the appearance of the mushroom.
 2. The product ofclaim 1 wherein said filamentous fungi is a mushroom.
 3. The product ofclaim 2 wherein said mushroom is selected from the group consisting ofAgaricus bisporus, Lentinula edodes, and Pleurotus ostreatus.
 4. Theproduct of claim 3 wherein said mushroom is Agaricus bisporus.
 5. Theproduct of claim 3 wherein said mushroom is Pleurotus ostreatus.
 6. Afilamentous fungi product including, tissues, substrate, spent substrateor components thereof with increased vitamin D content produced by thefollowing method: obtaining a filamentous fungi, tissue, substrate, orcomponent thereof to be enriched; exposing said filamentous fungi,tissue, substrate, or component thereof to pulsed UV irradiation from aUV-B source wherein said pulse is approximately 1-10 J/cm2 per pulse fora period of time of about 0.1 to about 60 seconds wherein approximately1-50 pulses per second are provided, so that Vitamin D is increasedwithout discoloration or deleterious effects on the appearance of themushroom; and removing said filamentous fungi tissue substrate orcomponent from said exposure.
 7. The product of claim 6 wherein saidfilamentous fungi is a mushroom.
 8. The product of claim 7 wherein saidmushroom is selected from the group consisting of Agaricus bisporus,Lentinula edodes, and Pleurotus ostreatus.
 9. The product of claim 8wherein said mushroom is Agaricus bisporus.
 10. The product of claim 9wherein said mushroom is Pleurotus ostreatu.
 11. The product of claim 6wherein said substrate or component is in powder form.